We were collecting field data from satellite imagery, such as soil moisture and plant conditions, but we needed to have ground reference data to validate that information. But that kind of data is tedious to collect and it's very hot work. The grad students who collected this information stayed in the field most of the day, and one of them was fainting from the heat. So I thought, what if we had a system that could collect data but could also convert the heat of the sun into an energy source? We could replace the grad student worker with a robotic system.

Once the robot was in the field, researchers kept improving it and have now added additional capabilities including a two-tiered approach to destroying weeds. The robot first cuts and removes the weed, then precisely applies a small amount of herbicide directly to the weed stump. This approach keep the herbicide on the weed and off the food plants, while at the same time greatly reducing the amounts of herbicide used. There's also some video of the weed robot and other UIUC ag robots in action after the jump.